[fawrth-klas, -klahs, fohrth-]
  1. as fourth-class matter; by fourth-class mail: Send it fourth-class.

fourth class

  1. (in the U.S. Postal Service) the class of mail consisting of merchandise weighing one pound or more, including parcel post and all first-, second-, or third-class matter weighing 8 ounces (227 grams) or more and not sealed against inspection.

Origin of fourth class

An Americanism dating back to 1860–65 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for fourth-class

Historical Examples of fourth-class

British Dictionary definitions for fourth-class


  1. of or relating to mail that is carried at the lowest rate
  1. by fourth-class mail
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012